Pirouette

How does the exhibit work?

Hold on to the pole. Spin around. The closer you hang to the pole, the faster you turn.

What is the science behind it?

Move your body away from the pole while spinning. Now move towards it. How do you the spin fastest?

The closer you are to the pole, the faster you turn. All the energy that used to be needed to make your body turn in a big circle is now put into a small circle. Therefore, with the same amount of energy, you turn much faster. We call this the law of conservation of angular momentum. Spin away!

Law of conservation of angular momentum in figure skating

What’s the trick for a good pirouette?

1. Start turning slowly with your arms or legs stretched out.
2. Make yourself small to reach top speed.

Law of conservation of angular momentum in stars

Stars also rotate around their axis. When a supergiant star collapses, it forms a neutron star. A neutron star is much more compact. The mass of the star therefore has to rotate in smaller circles. As a result, it rotates faster than the original supergiant.

A neutron star can rotate up to 700 times in one second!

Law of conservation of angular momentum in turning chairs

You can also easily test this law with a rotating office chair.

1. Sit on the chair with your arms stretched out and two weights in your hands.
2. Rotate.
3. Pull the weights towards you.